Bench Racing: Where does my 840 stand?

[TerryY]

If I were to wander off to the local strip

Who/What should I avoid? Other than the obvious Geo Metros?

Stock 840 performance data
0-50 = 5.5 seconds EDITED 0-60 is 7.4
1/4 mile = 15.4 seconds

Stock 850 is about 2 tenths faster on both.

I am chipped and have a few horsepower over the stock 850 so I should run the same or maybe a tenth quicker at best.

A bit over 300 crank hp and 300 foot pounds of torque pushing 4123 pound of car.

Before you laugh at how slow, remember they are factory speed limited to 155 MPH (250KPH) and aren't drag racers.

[ImageDynamicsM3]

you should fare well with most basic bolt-on modified hondas, mini-trucks, and many others that shouldn't even bother

[///Samson]

6 spd? If so, then you've got a nice monster. I bet if you could lighten her up just a little, stiffen the suspension to allow direct power towards the pavement, and let her breath better.... wow. That 4.4L would rise above. As time ticks on, I feel the 8 series calling me. . . my only concern is cost of major repair, but then again, - they're pretty much just as bullet proof as its brother - the 7. The V12 I know will rape the pocket-book when it needs fixin. I recall an 850 owner come into the dealership I worked at to get some engine repair. Two weeks after he came back in to trade in for a 540i - expressing dismay at the hit he took on the V12.

The 8 series body is the sexiest BMW shape ever made.... classy yet has that M1/Italian super car look

[TerryY]

It is a 5 speed Auto

BMW decided that no 840 6 speeds would be imported to the US. Only a few were made and all were sold elsewhere.

Somewhen I do plan to change the differential from somewhere around 2.95 now to 3.64 ratio.

[anj]

you should stay away from my jeeep, hahaha....you might take me 0-60, but I would beat you to the 1/4 by .4not to say i wouldn't trade you my Jeep and my left foot for your 840

[DSK M3/4]

0-60mph in 5.5? i'm surprised it's that quick. i would have thought it would be somewhere around 6.5.

[KC Ron Carter]

It will not affect the HP.

It just brings the torque to a point where it can be used.

If you change the ratio you will need to visit the traffic ticket forum.

Yep a few numbers will wake it up.

Later,

[TerryY]

Excuse me. I lied!!

Reread the Owners manual and 5.5 is the time for 0-50 not 0-60.

I'll put the dunce cap on and sit in the corner for a while.

Meanwhile I will edit the original post, Sorry.

[ajw45]

I'm not much of a drag racer, but I pulled slightly on a 996 cab from a roll from 1st through 3rd, and I'm running the super tall stock 2.65 differential. I think the biggest challenge is just getting the heavy sucker moving from a stop, once you're moving you're golden. I bet you could pull some great numbers with the diff upgrade and even a high stall torque converter to get the car moving fast off the line. I've also heard the Dinan tranny chip is great for 0-60 performance since it supposedly gives you faster shifting and more aggressive shift points. If the 540 can do 0-60 in 6 seconds with about the same weight and power, you definitely should be able to do better than that with the differential upgrade.

[stjobs]

"but I pulled slightly on a 996 cab from a roll from 1st through 3rd, and I'm running the super tall stock 2.65 differential."

I'm not going to call you a liar, but are you sure he was racing? The 996 cabriolet does 0-60 in approx. 5 seconds, and the 850 is around 7 seconds...

[TerryY]

It has enough go now to be fun. It came with the Dinan chips installed. The first thing I did was replace the engine ECU chip with one from Europe. That made a serious difference in both low end and mid range performance.

I took the future son-in-law on a short run and did one pass from 60 to 95 with the Dinan installed and he was pretty impressed. Then I changed chips to the Euro one and did the same 60 to 95 again. His response" What in the Hell did you do to it!!" It almost puts you in the back seat now.

The chipper claims 320 crank hp. Don't know if it is that high but it is a big noticeable jump over the 296 hp Dinan chip.

It has a completely different sound at both low rpm (exaust burble) and high throttle openings (air). Moans like a big 4 barrel now!! It hangs the tail out quite easily in standing start turns even with the ASC on!! With ASC off it ends up trying really hard to go sideways with a good aroma of hot rubber and mild spinning tire sounds. I usually have to let up to straighten it out.

I've got a couple of 850 chip sets but have never installed a set and seen what difference they would make. Got the V8 chip in both the 7 and 8.

The K-bars are coming soon. The H&Rs, K-Macs and Bilstiens are on now.

[RobH]

Conversation at a stop light:

Some ricer kid: "dude that car is old and slow"

You: "yeah but I look good"

That is a damn fine looking car. If someone wants to race, just make sure you start at about 70 mph. You shouldn't have any problems.

[ajw45]

Originally posted by stjobs
"but I pulled slightly on a 996 cab from a roll from 1st through 3rd, and I'm running the super tall stock 2.65 differential."

I'm not going to call you a liar, but are you sure he was racing? The 996 cabriolet does 0-60 in approx. 5 seconds, and the 850 is around 7 seconds...

Perhaps it was a tiptronic. The 996 cab 6spd is 5.0, tiptronic is listed at 5.5, and the 850i 6spd is listed at 6.1 for the 0-60 run. The 996 sounded like WOT to me. I lost a little ground in first, stayed even in second, and I started making it up in 3rd. I was pretty surprised too that he didn't just leave me. I've also had many slower cars than the porsche obliterate me off the line, but I chalk that up to my raw lack of skill launching a car.

[Hyperion]

Your biggest draw back is your weight. At 4100 pounds the 840 is no lightweight. Most of the cars you would find at the track would be about half of that weight. Lightening up the car would be your best move, but I know whats in an 8, and unless you want to stip the interior you don't really have an option. The problem is that the suspension and frame is so damn heavy, and there is nothing you can really do about that.

[TerryY]

Making it Less than a complete 8 is not an option.

I suppose that I don't have any choice but re-gearing and generating more Horsepower if that isn't enough.

It is a lot of fun to drive as is. It is just pokey till about 20-25 mph.
Then it feels quite adequate! I was playing with a G-tech at one point and hit what it said was .78 G acceleration in first. I didn't get any worthwhile 0-60's--too many hills and too much traffic where I was.

[SilverStreak]

Take it to the drag strip, run it once or twice, you'll have some fun, learn a few things, and no more speculation required.

You have an automatic, it's an easy launch, let us know how you do...

[Dark Helmet]

oh, and the 850 chips are worthless, send them to me!!! (serious, on both accounts! )

the 850 ECU is completely different from your 840, they each control one 6-cylinder engine... (with inputs and variances for the associated adjacent six)... they will not work with your V8.

now, the only other thing to do is get a pedal box and a 540 transmission and give yourself a big boost in the efficiency and gearing department... but keep the auto-trans gears!

[TerryY]

There are actually 3 chips to an 750/850 set. One for each ECU and a third for the throttle computer (EML?) to open the speed limiter.

Us 740/840 guys get lucky and only need one chip!!

I have sets for both motors so if you are interested, email me.
Much cheaper than Dinan or Conforti and your money back if you don't see a worthwhile change...... I really don't want to be in the business of selling chips but I have these and need to cash them out.